It is known that in about 0.5% of cancer patients, e.g., those suffering from malignant melanomas, the tumor reverses completely. In many cancer patients, a control of the tumor also takes place, so that it remains in a stable condition over years. This may be because the immune system influences the course of the cancer.
Many attempts have been made to activate the immune system, and to detect and eliminate tumor cells. However, these attempts have not yet yielded satisfactory results.
It is an object of the present invention to provide a product by which the immune system can be stimulated with respect to tumor cells.
Adeno-associated viruses (AAVs) are single-stranded DNA viruses belonging to the Parvovirus family. AAVs require helper viruses, particularly adenoviruses or herpesviruses, for their replication. In the absence of helper viruses AAVs integrate into the host cell genome, particularly at a specific site on chromosome 19.
The genome of AAVs is linear and has a length of about 4680 nucleotides. It comprises two reading frames which code for a structural gene and a non-structural gene. The structural gene is referred to as cap gene. It is controlled by the P40 promoter and codes for three capsid proteins. The non-structural gene is referred to as rep gene and codes for the rep proteins, Rep 78, Rep 68, Rep 52 and Rep 40. The two former proteins are expressed under the control of the P5 promoter while the expression of Rep 52 and Rep 40 is controlled by the P19 promoter. The functions of the Rep proteins are determined inter alia by the control of replication and transcription of the AAV genome.